Structure for attaching buttress material to anvil and cartridge of surgical stapling instrument

ABSTRACT

An end effector of a surgical stapler includes first and second jaw members and a buttress material. The first jaw member is moveable relative to the second jaw member. The first jaw member includes a contact surface, a first projection, and a catch. The catch includes first and second fingers distal of the first projection. The second finger is biased toward the contact surface. The buttress material defines a longitudinal axis. The buttress material is releasably secured to the first jaw member. The buttress material defines first, second, and third slots formed therein. The first projection of the first jaw member is received in the first slot of the buttress material. The first finger of the catch is received in the second slot of the buttress material.

BACKGROUND Technical Field

The present disclosure relates to attachment systems for staple line buttress materials, and more particularly, to systems and methods for detachably securing staple line buttress materials to an anvil and a staple cartridge of a surgical stapling instrument.

Background of Related Art

Surgical stapling instruments are employed by surgeons to sequentially or simultaneously apply one or more rows of fasteners, e.g., staples or two-part fasteners, to body tissue for the purpose of joining segments of body tissue together. When stapling relatively thin or fragile tissues, it is important to effectively seal the staple line against air or fluid leakage. Additionally, it is often necessary to reinforce the staple line against the tissue to prevent tears in the tissue or pulling of the staples through the tissue. One method of preventing tears or pull through involves the placement of a biocompatible reinforcing material or “buttress” material, between the staple and the underlying tissue. In this method, a layer of buttress material is placed against the tissue and the tissue is stapled in the conventional manner.

Accordingly, new systems and methods that are reliable and that enable easy and efficient attachment and removal of a buttress material to the surgical stapling instruments would be desirable.

SUMMARY

The present disclosure describes attachment structures for securing a buttress material to a surgical stapler that demonstrate a practical approach to meeting the performance requirements and overcoming the usability challenges associated with buttress material attachment and removal. In general, the present disclosure describes a surgical stapler that includes a handle assembly, an elongate member extending from the handle assembly, and an end effector operatively coupled with the handle assembly.

In accordance with an embodiment of the present disclosure, there is provided an end effector of a surgical stapler. The end effector includes first and second jaw members and a buttress material. The first jaw member is moveable relative to the second jaw member. The first jaw member includes a contact surface, a first projection, and a catch. The catch includes first and second fingers distal of the first projection. The second finger is biased toward the contact surface. The buttress material defines a longitudinal axis. The buttress material is releasably secured to the first jaw member. The buttress material defines first, second, and third slots formed therein. The first projection of the first jaw member is received in the first slot of the buttress material. The first finger of the catch is received in the second slot of the buttress material.

In an embodiment, the first and second fingers of the catch may be formed of an elastic material. In addition, the first and second fingers of the catch may define an acute angle with respect to each other. The second finger of the catch may include a head portion and a neck portion. The head portion may be configured to engage the contact surface of the first jaw member. The head portion may define a first width. The neck portion may define a second width smaller than the first width.

In another embodiment, the first jaw member may include an anvil assembly.

In another embodiment, the buttress material may be transitionable between an unexpanded state and an expanded state.

In another embodiment, the second and third slots of the buttress material may be adjacent to each other.

In yet another embodiment, the second slot of the buttress material may be defined transverse to the longitudinal axis of the buttress material. In addition, the third slot of the buttress material may extend along a length of the longitudinal axis of the buttress material. In addition, a proximal portion of the buttress material may be tapered.

In accordance with another embodiment of the present disclosure, there is provided an end effector of a surgical stapler including first and second jaw members and a buttress material. The first jaw member is moveable relative to the second jaw member. The first jaw member includes a contact surface and a catch having first and second fingers. The second finger biased toward the contact surface. The second jaw member includes first and second projections. The second projection is distal of the first projection. The buttress material defines a longitudinal axis. The buttress material is releasably secured with at least one of the first or second jaw members. The buttress material defines first, second, and third slots formed therein. The first projection of the second jaw member is received in the first slot of the buttress material when the buttress material is secured with the second jaw member. The first finger of the catch is received in the second slot of the buttress material when the buttress material is secured with the first jaw member, and the second projection of the second jaw member is received in the third slot of the buttress material when the buttress material is secured with the second jaw member.

In accordance with yet another embodiment of the present disclosure, there is provided a buttress material for use with a surgical stapling instrument. The buttress material includes an elongate body defining a longitudinal axis. The elongate body includes proximal and distal portions. The proximal portion includes a tapered portion. Further, the proximal portion defines first and second proximal slots separated by a wall. The first and second proximal slots extend transverse to the longitudinal axis. In addition, the distal portion defines first and second distal slots. In particular, the first distal slot is defined transverse to the longitudinal axis, and the second distal slot extends along a length of the longitudinal axis. The second distal slot is distal of the first distal slot.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein:

FIG. 1 is a perspective view of a surgical stapling instrument including buttress retention assemblies for attaching buttress materials to an anvil and a staple cartridge of the surgical stapling instrument in accordance with an embodiment of the present disclosure;

FIG. 2 is a perspective view of a jaw assembly of the surgical stapling instrument of FIG. 1, illustrating a buttress material secured with the staple cartridge;

FIG. 3 is a top view of the buttress material of FIG. 2 configured for use with the anvil and the staple cartridge of the surgical stapling instrument of FIG. 1;

FIG. 4 is a partial perspective view of the anvil and the buttress material of FIG. 3 in accordance with an embodiment of the present disclosure;

FIG. 5 is a partial perspective view of the buttress material and an anvil buttress retention assembly of FIG. 4;

FIG. 6 is a partial perspective view of a proximal portion of the staple cartridge of the surgical stapling instrument of FIG. 1;

FIG. 7 is a partial perspective view of a distal portion of the staple cartridge of the surgical stapling instrument of FIG. 1;

FIG. 8 is a perspective view of a distal end of the surgical stapling instrument of FIG. 1;

FIG. 9 is a partial cross-sectional view of the distal end of the surgical stapling instrument as taken through 9-9 of FIG. 8;

FIG. 10 is a partial cross-sectional view of the distal end of the surgical stapling instrument of FIG. 9, illustrating actuation of the surgical stapling instrument;

FIG. 11 is a perspective view of a stapled and divided tissue section; and

FIG. 12 is a cross-sectional view of the stapled and divided tissue section as taken through 12-12 of FIG. 11.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein, the term “distal” refers to that portion of a device that is farther from the user, while the term “proximal” refers to that portion of a device that is closer to the user.

With reference to FIG. 1, there is provided a surgical stapler 10 for use in stapling tissue and applying a layer of buttress material between staples and underlying tissue. Surgical stapler 10 generally includes a handle 12 and an elongate tubular member 14 extending distally from handle 12. A jaw assembly 16 is mounted on a distal end 18 of elongate tubular member 14. Jaw assembly 16 includes an anvil 20 and a staple cartridge 22. Anvil 20 is movable between an open position configured to receive tissue “T” (FIG. 8) between anvil 20 and staple cartridge 22 and a closed position configured to clamp “T” between anvil 20 and staple cartridge 22.

With continued reference to FIG. 1, surgical stapler 10 includes a trigger 32 movably mounted on handle 12. Actuation of trigger 32 is configured to move anvil 20 from the open position to the closed position and subsequently actuate surgical stapler 10 to apply lines of staples 178 (FIG. 9) to tissue “T”. In order to provide proper orientation of jaw assembly 16 relative to tissue to be stapled, surgical stapler 10 is additionally provided with a rotation knob 35 mounted on handle 12. Rotation of rotation knob 35 about a longitudinal axis “A-A” of surgical stapler 10 rotates elongate tubular member 14 and jaw assembly 16 about longitudinal axis “A-A.”

With reference now to FIG. 2, a driver 36 is provided to move anvil 20 between the open and closed positions relative to staple cartridge 22. Driver 36 moves along a longitudinal slot 38 defined in anvil 20. A knife blade 70 (FIGS. 4 and 5) is associated with driver 36 to cut tissue “T” captured between anvil 20 and staple cartridge 22 as driver 36 passes through longitudinal slot 38. In order to secure staples 178 (FIG. 9) provided by staple cartridge 22 about tissue “T” and buttress materials 24, anvil 20 is provided with longitudinally arranged rows of staple clinching or forming pockets 44 (FIG. 9) located on either side of longitudinal slot 38. Reference may be made to U.S. Pat. No. 7,128,253, filed on Jul. 20, 2005, entitled “Surgical Stapler,” the entire content of which is incorporated herein by reference, for a detailed discussion of the construction and operation of surgical stapler 10.

With reference to FIG. 3, there is provided a buttress material 24 in accordance with the present disclosure. Buttress material 24 reinforces and seals staple lines applied to tissue “T” by surgical stapler 10. Buttress material 24 is configured for use with both anvil 20 and staple cartridge 22. Buttress material 24 may be detachably secured with anvil 20 or staple cartridge 22. Buttress material 24 includes an elongate body 23 having proximal and distal portions 24 a, 24 b. In particular, proximal portion 24 a includes a tapered portion 25 defining proximal slots 23 a separated by a wall 27. Each proximal slot 23 a is defined transverse to a longitudinal axis “X-X” defined by buttress material 24. Distal portion 24 b of buttress material 24 defines a first distal slot 28 a and a second distal slot 28 b distal of the first distal slot 28 a. First distal slot 28 a is defined transverse to longitudinal axis “X-X” defined by buttress material 24, and second distal slot 28 b is extends along a length of longitudinal axis “X-X”. First and second distal slots 28 a, 28 b may be, e.g., orthogonal, to each other. In addition, buttress material 24 further includes a tab 31 configured to facilitate gripping of buttress material 24 by the clinician.

With reference now to FIGS. 4 and 5, anvil 20 includes a buttress retention assembly 29. In particular, buttress retention assembly 29 includes a support or sled 33 and a resilient catch 34 extending from support 33. Catch 34 include first and second fingers 34 a, 34 b. A portion of first finger 34 a is dimensioned to be received within first distal slot 28 a of buttress material 24. First finger 34 a may define an angle of about 5 degrees with respect to an axis perpendicular to longitudinal axis “X-X” of buttress material 24. First finger 34 a may be configured to substantially inhibit relative movement between buttress material 24 and first finger 34 a in, e.g., longitudinal and/or lateral directions. First and second fingers 34 a, 34 b may define an acute angle with respect to each other. Catch 34 further includes a neck portion 34 c extending from second finger 34 b and a head portion 34 d extending from neck portion 34 c. Head portion 34 d of catch 34 is configured to engage contact surface 20 a (FIG. 4) of anvil 20 to stabilize first finger 34 a received within first distal slot 28 a of buttress material 24.

In particular, first and second fingers 34 a, 34 b of catch 34 are formed of elastic and/or compressible material to enable flexing to facilitate engagement and/or disengagement of first and second fingers 34 a, 34 b with/from respective first distal slot 28 a of buttress material 24 and contact surface 20 a of anvil 20. Furthermore, second finger 34 c of catch 34 may be biased toward contact surface 20 a of anvil 20 in the direction of arrow “V” (FIG. 5) to further enhance securement of buttress material 24 on anvil 20.

In addition, a proximal portion of anvil 20 may further include proximal protrusions 20 b (FIG. 9) such as, e.g., bosses or hooks, extending proximally outward from contact surface 20 a of anvil 20. Proximal protrusions 20 b are dimensioned to be received in respective proximal slots 23 a of buttress material 24. Proximal slots 23 a and first distal slot 28 a of buttress material 24 are positioned such that in order to place the proximal protrusions 20 b of anvil 20 into respective proximal slots 23 a and to place first finger 34 a of catch 34 into first distal slot 28 a of buttress material 24, buttress material 24 is stretched to the expanded state and proximal protrusions 20 b are forced through respective proximal slots 23 a and first finger 34 a is received through first distal slot 28 a. In this manner, once buttress material 24 is secured with anvil 20, buttress material 24 may be released from the expanded state to transition towards the unexpanded state which, in turn, provides securement of buttress material 24 on anvil 20. Such a configuration maintains buttress material 24 taut across contact surface 20 a of anvil 20 and facilitates passage of surgical stapler 10 into the body of a patient as surgical stapler 10 is inserted into and manipulated within the body of the patient.

With reference to FIGS. 6 and 7, buttress material 24 may also be mounted on staple cartridge 22 prior to stapling of tissue “T”. Buttress material 24 reinforces and seals staple lines applied to tissue “T” by surgical stapler 10. Staple cartridge 22 is provided with rows of staple pockets 18 and a knife channel 414 that passes longitudinally between rows of staple pockets 18. Staple cartridge 22 includes a cartridge buttress retention assembly 428 including proximal fingers 423 a disposed on opposing sides of knife channel 414. Staple cartridge 22 includes a mount 433 that is transversely sloped or angled. Proximal fingers 423 a extend proximally from mount 433. Mount 433 may be configured to provide a planar contact with buttress material 24 thereon. A gap 450 is defined between each proximal finger 423 a and a contact surface 420 a of staple cartridge 22 to receive buttress material 24 therein. In particular, proximal fingers 423 a are configured to be received through respective proximal slots 23 a (FIG. 3) of buttress material 24.

With particular reference now to FIG. 7, a distal end portion 435 of staple cartridge 22 defines a cavity 451 dimensioned to receive a finger 423 c. Cartridge buttress retention assembly 428 includes a distal tooth 423 b extending from finger 423 c. Finger 423 c is configured for slight flexing to facilitate engagement and disengagement of buttress material 24 on tooth 423 b. In addition, distal tooth 423 b is dimensioned to be received through second distal slot 28 b (FIG. 3) of buttress material 24.

In use, with reference back to FIGS. 3 and 5, the proximal protrusions 20 b (FIG. 9) in the proximal portion of anvil 20 are inserted through proximal slots 23 a of buttress material 24. Thereafter, elastic buttress material 24 is stretched to the expanded state such that first finger 34 a of catch 34 is received through first distal slot 28 a to thereby secure buttress material 24 with anvil 20. Alternatively, buttress material 24 may also be secured with staple cartridge 22 as discussed hereinabove.

With reference now to FIGS. 8-10, jaw assembly 16 is positioned adjacent tissue “T” to be stapled. Driver 36 is in a proximal position relative to anvil slot 38. Staple cartridge 22 includes staples 178 positioned within respective staple pockets 18. Staples 178 are of a conventional type and include a backspan 182 having a pair of legs 184 and 186 extending from backspan 182. Legs 184 and 186 terminate in tissue penetrating tips 188 and 190. Pushers 192 are located within staple pockets 18 and are positioned between staples 178 and the path of a drive bar 194.

With particular reference to FIGS. 9 and 10, surgical stapler 10 is initially actuated by movement of trigger 32 relative to handle 12 (FIG. 1) causing driver 36 to move in the direction of arrow “B” and against sloped edge 40 of anvil 20 thereby causing anvil 20 to be moved to the closed position relative to staple cartridge 22. As drive bar 194 advances distally, drive bar 194 urges pushers 192 upwardly against backspans 182 of staples 178 driving staples 178 through buttress material 24 mounted on staple cartridge 22, tissue “T”, and buttress material 24 mounted on anvil 20 and towards staple clinching pockets 44 in anvil 20. Tissue penetrating tips 188 and 190 are bent within staple clinching pockets 44 in anvil 20 to thereby secure buttress material 24 mounted on anvil 20 against tissue “T” while backspan 182 secures buttress material 24 mounted on staple cartridge 22 against tissue “T”.

Upon full actuation of surgical stapler 10, knife blade 70 (FIG. 5) associated with surgical stapler 10 and carried by driver 36 cuts tissue “T”, as well as buttress materials 24 on opposing sides of tissue “T”, between the rows of now clinched staples 178. In addition, driver 36 operatively engages support 33 of buttress retention assembly 29 and causes concomitant movement of support 33. The distal movement of support 33 causes first finger 34 a of catch 34 to be disengaged from first distal slot 28 a of buttress material 24 to facilitate release of buttress material 24 from anvil 20.

Upon movement of anvil 20 to the open position spaced apart from staple cartridge 22, buttress materials 24 pull away from respective anvil 20 and staple cartridge 22. The resulting tissue “T” is divided and stapled with staples 178. Specifically, buttress material 24 that was mounted on staple cartridge 22 is secured against tissue “T” by backspans 182 of staples 178 and buttress material 24 that was mounted on anvil 20 is secured against tissue “T” by the now clinched tissue penetrating tips 188 and 190 of staples 178. In this manner, buttress materials 24 are stapled to tissue “T” thereby sealing and reinforcing the staple lines created by staples 178.

Buttress material 24 may have a substantially elongate rectangular profile. It is further contemplated that buttress material 24 may have a relatively thin, planar profile. In addition, buttress material 24 may be made from any biocompatible natural or synthetic material. The material from which the buttress material is formed may be bioabsorbable or non-bioabsorbable. It should of course be understood that any combination of natural, synthetic, bioabsorbable and non-bioabsorbable materials may be used to form the buttress material.

Some non-limiting examples of materials from which the buttress material may be made include but are not limited to poly(lactic acid), poly (glycolic acid), poly (hydroxybutyrate), poly (phosphazine), polyesters, polyethylene glycols, polyethylene oxides, polyacrylamides, polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinyl alcohols, polyacrylic acid, polyacetate, polycaprolactone, polypropylene, aliphatic polyesters, glycerols, poly(amino acids), copoly (ether-esters), polyalkylene oxalates, polyamides, poly (iminocarbonates), polyalkylene oxalates, polyoxaesters, polyorthoesters, polyphosphazenes and copolymers, block copolymers, homopolymers, blends and combinations thereof.

In embodiments, natural biological polymers are used in forming the buttress material. Suitable natural biological polymers include, but are not limited to, collagen, gelatin, fibrin, fibrinogen, elastin, keratin, albumin, hydroxyethyl cellulose, cellulose, hydroxypropyl cellulose, carboxyethyl cellulose, chitan, chitosan, and combinations thereof. In addition, the natural biological polymers may be combined with any of the other polymeric materials described herein to produce the buttress material.

The buttress material may be porous or non-porous, or combinations of porous and non-porous layers. Where the buttress material is non-porous, buttress material may retard or prevent tissue ingrowth from surrounding tissues thereby acting as an adhesion barrier and preventing the formation of unwanted scar tissue. Thus, in embodiments, the buttress material possesses anti-adhesion properties. Techniques for forming non-porous layers from such materials are within the purview of those skilled in the art and include, for example, casting, molding and the like.

In embodiments, the buttress material is porous and possesses hemostatic properties. Where the buttress material is porous, it has openings or pores over at least a portion of a surface thereof. Suitable materials for forming the porous layer include, but are not limited to foams (e.g., open or closed cell foams). In embodiments, the pores may be in sufficient number and size so as to interconnect across the entire thickness of the porous layer. In other embodiments, the pores do not interconnect across the entire thickness of the porous layer. In yet other embodiments, the pores do not extend across the entire thickness of the porous layer, but rather are present at a portion of the surface thereof. In embodiments, the openings or pores are located on a portion of the surface of the porous layer, with other portions of the porous layer having a non-porous texture. Those skilled in the art reading the present disclosure will envision other pore distribution patterns and configurations for the porous layer.

Where the buttress material is porous, the pores may be formed using any method suitable to forming a foam or sponge including, but not limited to the lyophilization or freeze-drying of a composition. Suitable techniques for making foams are within the purview of those skilled in the art. Porous buttress materials can be at least 0.2 cm thick, in embodiments from about 0.3 to about 1.5 cm thick. Porous buttress materials can have a density of not more than about 75 mg/cm² and, in embodiments below about 20 mg/cm². The size of the pores in the porous buttress materials can be from about 20 μm to about 300 μm, in embodiments from about 100 μm to about 200 μm.

The buttress material may also include a reinforcement member. The reinforcement member may be associated with a porous or non-porous layer or may be positioned between a non-porous layer and a porous layer of the buttress material. Alternatively, the reinforcement member may be positioned entirely within one or more of the individual layers (i.e., embedded within the porous layer, the non-porous layer, or both) of the buttress material. It is also envisioned that the reinforcement member may be positioned at the surface of one of the layers making up the buttress material and, in embodiments, may be positioned at an exterior surface of the buttress material.

Some suitable non-limiting examples of reinforcement members include fabrics, meshes, monofilaments, multifilament braids, chopped fibers (sometimes referred to in the art as staple fibers) and combinations thereof. Where the reinforcement member is a mesh, it may be prepared using any technique known to those skilled in the art, such as knitting, weaving, tatting, knipling or the like. Where monofilaments or multifilament braids are used as the reinforcement member, the monofilaments or multifilament braids may be oriented in any desired manner. For example, the monofilaments or multifilament braids may be randomly positioned with respect to each other within the buttress material. As another example, the monofilaments or multifilament braids may be oriented in a common direction within the buttress material. Where chopped fibers are used as the reinforcement member, the chopped fibers may be oriented in any desired manner. For example, the chopped fibers may be randomly oriented or may be oriented in a common direction. The chopped fibers can thus form a non-woven material, such as a mat or a felt. The chopped fibers may be joined together (e.g., by heat fusing) or they may be unattached to each other. The chopped fibers may be of any suitable length. For example, the chopped may be from 0.1 mm to 100 mm in length, in embodiments, 0.4 mm to 50 mm in length. In an illustrative embodiment, the buttress material has randomly oriented chopped fibers that have not been previously fused together embedded within in the buttress material.

It is envisioned that the reinforcement member may be formed from any bioabsorbable, non-bioabsorbable, natural, or synthetic material previously described herein and combinations thereof. Where monofilaments or multifilament braids are used as the reinforcement member, any commercially available suture material may advantageously be employed as the reinforcement member.

In embodiments, at least one bioactive agent may be combined with the buttress material and/or any of the individual components (the porous layer, the non-porous layer and/or the reinforcement member) used to construct the buttress material. In these embodiments, the buttress material can also serve as a vehicle for delivery of the bioactive agent. The term “bioactive agent”, as used herein, is used in its broadest sense and includes any substance or mixture of substances that have clinical use. Consequently, bioactive agents may or may not have pharmacological activity per se, e.g., a dye, or fragrance. Alternatively a bioactive agent could be any agent which provides a therapeutic or prophylactic effect such as a compound that affects or participates in tissue growth, cell growth, or cell differentiation.

Examples of classes of bioactive agents which may be utilized in accordance with the present disclosure include anti-adhesives, antimicrobials, analgesics, antipyretics, anesthetics, antiepileptics, antihistamines, anti-inflammatories, cardiovascular drugs, diagnostic agents, sympathomimetics, cholinomimetics, antimuscarinics, antispasmodics, hormones, growth factors, muscle relaxants, adrenergic neuron blockers, antineoplastics, immunogenic agents, immunosuppressants, gastrointestinal drugs, diuretics, steroids, lipids, lipopolysaccharides, polysaccharides, and enzymes. It is also intended that combinations of bioactive agents may be used.

Anti-adhesive or anti-adhesion agents can be used to prevent adhesions from forming between the buttress material and the surrounding tissues opposite the target tissue. Some examples of these agents include, but are not limited to poly(vinyl pyrrolidone), carboxymethyl cellulose, hyaluronic acid, polyethylene oxide, poly vinyl alcohols and combinations thereof.

Suitable antimicrobial agents which may be included as a bioactive agent in the buttress material of the present disclosure include triclosan, also known as 2,4,4′-trichloro-2′-hydroxydiphenyl ether, chlorhexidine and its salts, including chlorhexidine acetate, chlorhexidine gluconate, chlorhexidine hydrochloride, and chlorhexidine sulfate, silver and its salts, including silver acetate, silver benzoate, silver carbonate, silver citrate, silver iodate, silver iodide, silver lactate, silver laurate, silver nitrate, silver oxide, silver palmitate, silver protein, and silver sulfadiazine, polymyxin, tetracycline, aminoglycosides, such as tobramycin and gentamicin, rifampicin, bacitracin, neomycin, chloramphenicol, miconazole, quinolones such as oxolinic acid, norfloxacin, nalidixic acid, pefloxacin, enoxacin and ciprofloxacin, penicillins such as oxacillin and pipracil, nonoxynol 9, fusidic acid, cephalosporins, and combinations thereof. In addition, antimicrobial proteins and peptides such as bovine lactoferrin and lactoferricin B may be included as a bioactive agent in the bioactive coating of the present disclosure.

Other bioactive agents which may be included as a bioactive agent in the buttress material in accordance with the present disclosure include: local anesthetics; non-steroidal antifertility agents; parasympathomimetic agents; psychotherapeutic agents; tranquilizers; decongestants; sedative hypnotics; steroids; sulfonamides; sympathomimetic agents; vaccines; vitamins; antimalarials; anti-migraine agents; anti-parkinson agents such as L-dopa; antispasmodics; anticholinergic agents (e.g. oxybutynin); antitussives; bronchodilators; cardiovascular agents such as coronary vasodilators and nitroglycerin; alkaloids; analgesics; narcotics such as codeine, dihydrocodeinone, meperidine, morphine and the like; non-narcotics such as salicylates, aspirin, acetaminophen, d-propoxyphene and the like; opioid receptor antagonists, such as naltrexone and naloxone; anti-cancer agents; anti-convulsants; anti-emetics; antihistamines; anti-inflammatory agents such as hormonal agents, hydrocortisone, prednisolone, prednisone, non-hormonal agents, allopurinol, indomethacin, phenylbutazone and the like; prostaglandins and cytotoxic drugs; estrogens; antibacterials; antibiotics; anti-fungals; anti-viral s; anticoagulants; anticonvulsants; antidepressants; antihistamines; and immunological agents.

Other examples of suitable bioactive agents which may be included in the coating composition include viruses and cells, peptides, polypeptides and proteins, analogs, muteins, and active fragments thereof, such as immunoglobulins, antibodies, cytokines (e.g. lymphokines, monokines, chemokines), blood clotting factors, hemopoietic factors, interleukins (IL-2, IL-3, IL-4, IL-6), interferons (β-IFN, (α-IFN and γ-IFN), erythropoietin, nucleases, tumor necrosis factor, colony stimulating factors (e.g., GCSF, GM-CSF, MCSF), insulin, anti-tumor agents and tumor suppressors, blood proteins, gonadotropins (e.g., FSH, LH, CG, etc.), hormones and hormone analogs (e.g., growth hormone), vaccines (e.g., tumoral, bacterial and viral antigens); somatostatin; antigens; blood coagulation factors; growth factors (e.g., nerve growth factor, insulin-like growth factor); protein inhibitors, protein antagonists, and protein agonists; nucleic acids, such as antisense molecules, DNA and RNA; oligonucleotides; polynucleotides; and ribozymes.

Persons skilled in the art will understand that the structures and methods specifically described herein and shown in the accompanying figures are non-limiting exemplary embodiments, and that the description, disclosure, and figures should be construed merely as exemplary of particular embodiments. For example, the projections of anvil or staple cartridge may be slightly larger in size than the apertures or slots of buttress materials, thereby providing an interference fit upon insertion of the projections into the apertures or slots. The projections and the corresponding apertures and slots may have any geometry best suited for retaining the projections within the apertures or slots. In addition, various numbers of fingers or projections may be provided to increase the frictional contact between a jaw member and an associated buttress material.

It is to be understood, therefore, that the present disclosure is not limited to the precise embodiments described, and that various other changes and modifications may be effected by one skilled in the art without departing from the scope or spirit of the disclosure. Additionally, the elements and features shown or described in connection with certain embodiments may be combined with the elements and features of certain other embodiments without departing from the scope of the present disclosure, and that such modifications and variations are also included within the scope of the present disclosure. Accordingly, the subject matter of the present disclosure is not limited by what has been particularly shown and described. 

What is claimed is:
 1. An end effector of a surgical stapler, comprising: first and second jaw members, the first jaw member moveable relative to the second jaw member, the first jaw member including a contact surface, a first projection, and a catch, the catch including first and second fingers distal of the first projection, the second finger biased toward the contact surface; and a buttress material defining a longitudinal axis, the buttress material releasably secured to the first jaw member, the buttress material defining first, second, and third slots formed therein, the first projection of the first jaw member received in the first slot of the buttress material, the first finger of the catch received in the second slot of the buttress material.
 2. The end effector according to claim 1, wherein the first and second fingers of the catch are formed of an elastic material.
 3. The end effector according to claim 1, wherein the first and second fingers of the catch define an acute angle with respect to each other.
 4. The end effector according to claim 1, wherein the second finger of the catch includes a head portion and a neck portion, the head portion defining a first width, the neck portion defining a second width smaller than the first width.
 5. The end effector according to claim 4, wherein the head portion of the second finger may be configured to engage the contact surface of the first jaw member.
 6. The end effector according to claim 1, wherein the first jaw member includes an anvil assembly.
 7. The end effector according to claim 1, wherein the buttress material is transitionable between an unexpanded state and an expanded state.
 8. The end effector according to claim 1, wherein the second and third slots of the buttress material are adjacent to each other.
 9. The end effector according to claim 1, wherein the second slot of the buttress material is defined transverse to the longitudinal axis of the buttress material.
 10. The end effector according to claim 1, wherein the third slot of the buttress material extends along a length of the longitudinal axis of the buttress material.
 11. The end effector according to claim 1, wherein a proximal portion of the buttress material is tapered.
 12. An end effector of a surgical stapler, comprising: first and second jaw members, the first jaw member moveable relative to the second jaw member, the first jaw member including a contact surface and a catch having first and second fingers, the second finger biased toward the contact surface, the second jaw member including first and second projections, the second projection distal of the first projection; and a buttress material defining a longitudinal axis, the buttress material releasably secured with at least one of the first or second jaw members, the buttress material defining first, second, and third slots formed therein, the first projection of the second jaw member received in the first slot of the buttress material when the buttress material is secured with the second jaw member, the first finger of the catch received in the second slot of the buttress material when the buttress material is secured with the first jaw member, the second projection of the second jaw member received in the third slot of the buttress material when the buttress material is secured with the second jaw member.
 13. The end effector according to claim 12, wherein the first and second fingers of the catch are formed of an elastic material.
 14. The end effector according to claim 12, wherein the first and second fingers of the catch define an acute angle with respect to each other.
 15. The end effector according to claim 12, wherein the second finger of the catch includes a head portion and a neck portion, the head portion defining a first width, the neck portion defining a second width smaller than the first width.
 16. The end effector according to claim 15, wherein the head portion of the second finger is configured to engage the contact surface of the first jaw member.
 17. The end effector according to claim 12, wherein the first jaw member includes an anvil assembly.
 18. The end effector according to claim 12, wherein the buttress material is transitionable between an unexpanded state and an expanded state.
 19. The end effector according to claim 12, wherein the second slot of the buttress material is defined transverse to the longitudinal axis of the buttress material.
 20. The end effector according to claim 12, wherein the third slot of the buttress material is extends along a length of the longitudinal axis of the buttress material.
 21. A buttress material for use with a surgical stapling instrument, the buttress material comprising: an elongate body defining a longitudinal axis, the elongate body including proximal and distal portions, the proximal portion including a tapered portion, the proximal portion defining first and second proximal slots separated by a wall, the first and second proximal slots extending transverse to the longitudinal axis, the distal portion defining first and second distal slots, the first distal slot is defined transverse to the longitudinal axis, the second distal slot extends along a length of the longitudinal axis, the second distal slot distal of the first distal slot.
 22. The buttress material according to claim 21, wherein the elongate body includes a tab distal of the second distal slot. 